[19a-P2-1~13] 3.3 Information photonics and image engineering

[19a-P2-5] Recording Technique of Hologram and Expansion to Phase Multi-Level Signaling for High Capacity and High Speed Three Dimensional Optical Memory

〇Makoto Hosaka¹, Yusuke Nakamura¹, Kazuyuki Tajima¹, Takeru Utsugi¹, Toshiki Ishii¹, Kazuyoshi Yamazaki¹, Kenichi Shimada¹, Taku Hoshizawa¹ (1.Hitachi R&D)

Keywords:optical memory, hologram, phase multi-level signaling

Holographic memory has attracted considerable attention as a next generation storage for drastically increasing data in the world. We accomplished recording density of 1 Tbit/in² using the recording condition optimizing technique depending on signal-to-scatter ratio. In this study, we developed a high accurate phase reproduction technique depending on the angular spectrum of local oscillator light and reproduced light for n doubling of recording density. This technique is effective even for the signal recorded with poor wave front because the wave front of local oscillator is matched to the reproduced light.